Medical balloons have been widely used in medical procedures. Typically, an uninflated medical balloon is inserted into a body-space. When the medical balloon is inflated, the volume of the medical balloon expands, and the body-space is similarly expanded. In procedures such as angioplasty, the medical balloon may be used to open a collapsed or blocked artery.
Generally, medical balloons have been made of rubber or other compliant substances. To inflate the compliant medical balloons, pressure is increased within the medical balloon, causing the compliant substance to stretch. As more and more pressure is applied to the inner surface of the medical balloon, the medical balloon expands larger and larger until the medical balloon bursts. A typical medical balloon will burst at approximately 7-20 atmospheres or about 100-300 psi.
One of the principal difficulties in the use of medical balloons in medical procedures is controlling the dimensions of the inflated medical balloon. The pressure introduced must be sufficient to inflate the medical balloon to the proper size, however too much pressure may overinflate the balloon. Overinflating a medical balloon may cause the balloon to expand to a size that may cause stress on the body and may even damage the body. In the worst case, the excess of pressure may burst the balloon, which can lead to serious complications.
While medical balloons are typically made to close tolerances so that the inflation pressure of the balloon is predictable, variations in the materials used may cause compliant medical balloons to either under-inflate or overinflate for a given pressure. The equipment used to inflate and control the pressure of the balloon must be carefully calibrated and sufficiently accurate to deliver the expected pressure with minimal deviations.
Medical balloons are commonly used in angioplasty, orthopaedics and other medical procedures where it is necessary to force a space within the body.
Non-compliance, or the ability not to expand beyond a predetermined size on pressure and to maintain substantially a profile, is a desired characteristic for balloons. A non-compliant medical balloon is less likely to rupture or dissect the vessel as the balloon expands. The burst pressure of a balloon is the average pressure required to rupture a balloon; usually measured at body temperature.
Further difficulties often arise in guiding a balloon catheter into a desired location in a patient due to the friction between the apparatus and the vessel through which the apparatus passes. The result of this friction may be failure of the balloon due to abrasion and puncture during handling and use. Failure may also result from over-inflation.
Therefore, what is needed is a non-compliant medical balloon that can be inflated with pressure such that the balloon maintains its inflated dimensions without further expanding when additional pressure is applied.